Glossary: Bondage: Acts involving the physical restraint of a partner. Bondage typically refers to total restraint, however it can be limited to a particular body part, such as breast bondage. Glossary: Butt plug: Much like a dildo, but pear-shaped with a flared base. The flared base prevents the plug from being lost in the anal cavity; the pear shape helps hold the plug in place. They come in a variety of sizes; some can vibrate.